Means for controlling the tension on strips of flexible material drawn from flat coils



May 21, 1935. F, H FRY 2,001,780

MEANS FOR CONTROLLING THE TENSION ON STRIPS OF FLEXIBLE MATERIAL DRAWN FROM FLAT COILS Filed April 22. 1930 5 Sheets-Sheet 1 Fig. 1. A

2 5 7 I4 15 I2 X IN VE N 70/? May 21, 1935. F. H FRY 2,001,780

MEANS FOR CONTROLLING THE TENSION ON STRIPS OF FLEXTBLE MATERIAL DRAWN FROM FLAT COILS Filed April 22, 1950 3 Sheets-Sheet 2 Fig. 2.

HTTO/M/[M May 21, 1935. F H FRY 2,001,780

MEANS FOR CONTROLLING THE TENSION ON STRIPS OF FLEXIBLE MATERIAL DRAWN FROM FLAT cons Filed April 22, 1930. 5 Sheets-Sheet 5 Fig. 3.

BY 2 {WA-9M ATTORNEYS Patented May 21, 1935 UNITED STATES PATENT OFFICE MEANS FOR CONTROLLING THE TENSION N STRIPS 0F FLEXIBLE MATERIAL DRAWN FROM FLAT COILS Francis Henry Fry, Gravesend, England, aseignor to W. T. Henley: Telegraph Works Company, Limited, London. England, a British company Application April 22, 1930, Serial No. 446,286 In Great Britain May 10, 1929 6 Claims. (Cl. 242-15) This invention deals with the arrangements for Fig. 3 a similar view of a further modification. supporting fiat coils of flexible strip material, for In Fig. 1 a flat disc i is secured by means of the instance paper, which is drawn off from the coils bolts 2 and nuts 3 to a convenient support 4. The under tension. In arrangements of the kind central part of the disc i is formed with stepped 5 to which the invention relates the tension is conportions 5 and 6. The stepped portion 5 has 5 trolled by friction applied to one or both of the secured to it a bush 1 upon which a centre 8 for sides of the coil of material due to a pressure the coil 9 can rotate as the material is drawn tending to move nearer together the two discs off from the coil. The stepped portion 6 has a or frames or other members (hereinafter for bearing member l0 secured to it and which sup- 1 convenience referred to as discs) between which ports a dished disc ii, the latter being provided 10 the coil is carried. The object of the invenwith a sleeve or bush II. The bearing member tion is to so arrange the control of the tension ID has a hollow extension l3 which is screwthat it remains approximately constant in value threaded externally and internally. The dished as the strip is drawn off and the size of the disc II is maintained in position by means of a coil is diminished. This object is attained by nut H which is recessed to receive a ball bear- 15 arranging that the lateral pressure is applied so ing l5, and a spring l6 interposed between the as to act only on the outer part of the coil at dished disc II and the ball hearing I 5. The nut all stages of the drawing off. This is done by is prevented from rotating by a lock nut ll. A making one or both of the discs with a dished felt washer it may be placed against the fiat disc go inner surface so that this surface is not parall and rotate with the coil 9. The spring I6 lel with the corresponding surface of the other applies the necessary pressure to the dished disc disc so that the only part of the coil (which has ii and the dishing of the latter ensures that the parallel sides owing to the uniform width of the pressure is always applied to the periphery of the strip) gripped by the two discs is that part in coil irrespective of the diameter of the latter.

the immediate neighbourhood of the outer pe- The desired degree of pressure may be regu- 25 riphery from which the strip is being drawn off. lated by the nut it. As the coil 9 rotates its One of the discs may be held stationary while outer layers are pressed by the dished disc Ii the other is mounted so that it can rotate with against the yielding surface of the felt washer the coil, a spring for example, being employed l8 and the greater part of the frictional reto press the dished disc against the coil, the sistance resulting from the lateral pressure will 30 -dished disc being arranged to move towards the always act at a radius which is approximately fixed disc as the diameter of the coil becomes the radius of the outside of the coil. This tends reduced. to make the tension more nearly constant than The action may be assisted by lining one of would be the case if the disc ii had a fiat inner the discs with a layer of yielding material, such surface. Moreover owing to the fact that the 35 as felt, which is free to move relative to the disc. inner surface of the disc ii is dished, as the di- On the other hand, both devices may be alameter becomes reduced, during the unwinding lowed to rotate with the coil, the lateral presof the coil, the spring i6 causes the dished disc sure being obtained as before by means of a II to approach the fixed disc I, and so reducing spring. In addition to this spring -a relatively the pressure produced by the spring i6. This is 40 weak spring may be used. The lateral pressure of advantage for the following reason. In addiproduced by this spring is a comparatively light tion to the friction due to the lateral pressure one and has only a small effect compared with there is a further resisting friction due to the the main pressure during the earlier stages of pressure between the centre 8 upon which the the unwinding, but during the later stages, its coil 9 is mounted and the bush 1 or stepped por- 45 comparative effect upon the coil increases, when tion 5 on which the coil rotates. The importance the main pressure is reduced due to the relative of this component of the total resistance inmovement of the discs towards each other. The creases as the diameter of the coil decreases, and invention may be used with one or more coils. it is therefore desirable that the friction due to .0 Three forms of construction in accordance the lateral pressure should be falling off more with the invention are illustrated as examples rapidly than the diameter decreases. This effect in the accompanying drawings, wherein:- is produced by arranging the spring to function Fig. 1 is a sectional elevation of one form of as described above. 1" construction. In Fig. 2, two coils 9 are shown arranged side Fig. 2 a similar view of a modified form and by side upon a common hub is and as the ar- 55 rangements are the same for both coils, those for one of the coils only will now be described. The coil 9 is mounted upon a centre 8 between a dished disc I I and a flat disc I. The latter is secured to a ring 20 and the ring can rotate upon the hub I9. The central portion of the outer surface of the fiat disc I is recessed to receive a felt washer 2I which rotates with the hat disc I and is held in position by a metal ring 22. The hub I9 is screw threaded so that a nut 23 can be used to hold the fiat disc I in position. The dished disc II is supported upon a sleeve 24 which is keyed to the hub I9 so that it cannot rotate upon the hub but can slide along the hub. A spring I6 is housed in a recess 25 in the end of the hub I9 and presses against the sleeve 24. A felt washer 26 which rotates with the dished disc II is interposed between the outer surface of the dished disc II and the sleeve 24. A ring 21 holds the washer 26 and sleeve 24 in position and a ring 28 holds the ring 22 and washer 2I in position. In this case both discs rotate and the requisite restraint upon the coil against rotation is produced by the pressure exerted by the spring, and acting at the outer part of the coil and the friction between the stationary rings and the felt washers disposed between the rings and the discs. As the coil 9 becomes reduced in diameter during the unwinding process, the spring presses the dished disc I I towards the fiat disc I. The pressure exerted by the spring I6 can be adjusted by the nut 23. In the case of the outer coil an abutment for the spring may be provided in the form of a ring 29 which may be adjustable longitudinally of the hub I9 but is prevented from rotating.

Fig. 3 shows two coils 9 mounted upon a screw threadedspindle or hub 30 having a keyway 3|. Each coil has a centre 8 and the coil can rotate upon a ring or sleeve 32, the latter being screwed on to the fiat disc I which can also rotate. The latter is recessed to receive a felt washer 33 which rotates with the flat disc I and is held in place by a stepped metal ring 34. The dished disc II can rotate upon a flanged metal ring 35 and a rotatable felt washer 36 is interposed between the ring 35 and dished disc II. The rings 34 and 35 are keyed to the hub 30 so that they cannot rotate but can slide along the hub. A relatively weak spring 31 presses against the ring 35 and a stronger and stiffer spring I 6 is interposed between the spring 31 and a ring 38 secured to the end of the hub 30. The stepped ring 34 is used to support the dished disc II for the outer coil 9 and a rotatable felt washer 38' is placed between the stepped ring 34 and this dished disc. The outer coil 9 is carried upon a sleeve 32 as in the case of the first coil and a rotatable felt washer 39 is placed between the fiat disc for the outer coil and a ring 40 keyed to the hub 30. A nut 4| holds the two coils in position upon the hub 30 and controls the pressure exerted by the springs I6 and 31.

In this construction, the lateral pressure upon the coils is produced by the two springs, but the weaker spring 31 has a small effect only as compared with the main pressure produced by the other spring I6 during the earlier stages of the unwinding of the coils. During the later stages, however, the comparative effect of the weaker spring 31 upon the coils is increased, when the main pressure is reduced owing to the movement of the dished disc II towards the flat disc I. This construction has the advantage of steadying the tension upon the coils should there be any tendency for it to fluctuate during the later stages of the unwinding when the diameters of the coils are comparatively small. The necessary frictional restraint against rotation of the coils is produced as in the previous case by the spring pressure acting at the outer parts of the coils and the friction between the various stationary rings and their respective felt washers. Instead of employing the particular arrangement of springs as described with reference to Fig. 3 the dished disc itself might be formed as a springy member arranged to exert the major portion of the lateral pressure upon the coil during the earlier stages of the unwinding process, this pressure decreasing as before as the diameter of the coil was reduced. A weaker spring would then be arranged to move the disc along the hub and to have an increased comparative effect upon the coil during the later stages of the unwinding process. This arrangement might be employed with one or more coils.

What I claim as my invention and desire to secure by Letters Patent is:-

1. A device for controlling the tension of strip material as it is being drawn ofl from a flat coil comprising a carrier for the coil having two discs, one of which has a dished inner surface so as to make contact with the coil at the radially outer part of the latter, one of said discs being axially movable relative to the other, a fixed abutment, a relatively stiff spring and a weaker spring operating in conjunction between said abutment and the movable disc and tending to move the latter towards the fixed disc, the weaker spring being relatively ineffective during the earlier stages and relatively more effective during the latter stages of the unwinding of the coil than the stifler spring.

2. A device for controlling the tension of strip material as it is being drawn off from a fiat coil, comprising a carrier for the coil having two discs, one of which has a dished inner surface, and one of which is movable axially relative to the other, a fixed abutment, a spring acting between the fixed abutment and the axially movable disc to press the dished disc and the coil into contact with each other at the radially outer part of the coil, and the coil towards a fixed part of the carrier, so as to exert a braking action upon the rotation of the coil, the force exerted by the spring and the braking action upon the coil being reduced as the size of the coil is reduced.

3. A device for controlling the tension of strip material as it is being drawn off from a fiat coil, comprising a carrier for the coil having two discs, one of which has a dished inner surface, and one of which is axially movable relative to the other, a fixed abutment, a relatively stiff spring and a weaker spring operating in conjunction between the abutmentand the axially movable disc to press the dished disc and the coil into contact with each other at the radially outer part of the coil, and the coil towards a fixed part of the carrier to exert a braking action upon the rotation of the coil, the weaker spring being relatively ineffective in its action upon the axially movable disc during the earlier stages of the unwinding of the coil than the stiffer spring, and relatively more effective during the later stages of the unwinding of the coil as compared with the eflect produced by the stiffer spring.

4. A device for controlling the tension of strip material as it is being drawn oil from a fiat coil comprising a coil carrier adapted to make a comparatively close fit with the coil and having two discs between which the coil is adapted to be placed, and one of the discs having a dished inner surface so as to make contact with the coil only at the radially outer part of the latter, and means for applying a gradually reducing lateral pressure to the coil through the discs.

5. A device for controlling the tension of strip material as it' is being drawn off from a flat coil, comprising a coil carrier having a rotatably fixed disc, a freely rotatable second disc having a dished inner surface, one of said discs being axially movable, an axially fixed abutment and a spring interposed between the said abutment and the axially movable disc.

6. A device for controlling the tension of strip material as it is being drawn oif from a flat coil,

comprising a carrier for the coil having a rotatable but axially fixed disc, and a rotatable and axially movable disc, one of said discs having a dished inner surface, said axially movable disc approaching said axially fixed disc as the coil diameter is reduced, a fixed abutment, a spring interposed between the fixed abutment and the axially movable disc and exerting pressure upon the latter, the spring elongating and exerting a reducing pressure upon the axially movable disc as the latter moves towards the axially fixed disc, a friction member, and means for maintaining. the friction member bearing against the axially fixed disc.

FRANCIS HENRY FRY. 

